Should I tell him how I feel?

I have been seeing this guy for a few months now, we talk all day everyday, we hangout multiple times a week. We work together, different departments but the same building. Now mind you I knew right away what I wanted or I would have never started talking to him. And he has been very honest with me. But he ships out for the military in 2 months and we haven’t had that relationship defining discussion yet... and I know if he leaves before we do I will go crazy wondering while he is gone. And while I know how I feel and that I want more, and that if he wants the same from me I would be more than willing to wait for him, I don’t know if I should bring it up now or wait until it’s closer to him leaving... plus nine months of waiting for him to come back is nothing compared to a lifetime.